Device for fixing the back of a chair or the like to the supporting structure

Abstract: A device for fixing the back of a chair or the like to the supporting structure. The device comprises, at the end (15) of a vertical portion of the support (16) of the back, two oppositely arranged elastically retractable pins (17) which are suitable to fit in corresponding seats of shoulders (24) which extend from the internal structure (11) of the back and between which the end (15) is suitable to be inserted and guided.

Description: The present invention relates to a device for fixing the back of a chair or the like to the supporting structure. In some types of currently commercially available office chairs, the seat and the back are mounted on the ends of an L-shaped support. The back is substantially composed of an internal supporting structure which is provided, in an upward region, with a padding and a covering and is closed, in a downward region, by a covering shell which is made of plastics and has, at the rear, an opening for the passage of the corresponding end of the L-shaped support. This technical configuration entails that the various parts that compose the back are assembled during the final assembly of the chair, since it is impossible to work inside the back to fix the support. The manufacturers of the various components of the chairs must therefore supply loose parts or in any case parts that are only partially assembled, and this is a hardly negligible drawback in the field. A device with the features set forth in the preamble of claim 1 is known from the document GB-A-972 460. Therefore, an aim of the present invention is to provide a fixing device that allows to manufacture backs that are already assembled and are ready to easily and quickly compose chairs or the like in the combinations desired by the dealer. A consequent primary object is to provide a device that allows sturdy and reliable fixing. Another important object is to provide a fixing device which is simple to manufacture and has a low cost. This aim, these objects, and others which will become apparent hereinafter are achieved by a device for fixing the back of a chair or the like to the supporting structure, according to the invention and as claimed in claim 1. Further characteristics and advantages of the invention will become apparent from the following detailed description of an embodiment thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein: figure 1 is a partially cutout view from below of a back and of the support to which it is fixed; figure 2 is an enlarged-scale detail view of the elements that compose the device during fixing; figure 3 is a partially sectional view of the elements of the fixing device, coupled to each other; figure 4 is a partially sectional side view of the fixing device; figure 5 is a view from below of the device during fixing. With reference to the above figures, the back of a chair is generally designated by the reference numeral 10 and is composed of an internal shaped supporting plate 11, made for example of plastics, on top of which a padding with a covering 12 of fabric or other material is placed. A covering shell 13 is fixed in a rearward region to said plate 11 and has, in a downward region, an opening 14 in which the vertical end 15 of an L-shaped support, generally designated by the reference numeral 16, is inserted for fixing; a seat, not shown in the figures for the sake of simplicity, is conveniently fixed to the other end of said L-shaped support. According to the invention, two oppositely arranged elastically retractable coaxial pins 17 are rigidly coupled to said end 15 of the support 16. In particular, said pins 17 are accommodated in a transverse through hole 18 of an element 19 made of plastics which is fixed to the end 15 at its bottom. Each pin 17 has a wider disk-like end 20 that is slideable in a corresponding wider region 21 of the hole 18, and a cylindrical helical spring 22 is interposed between the two ends 20. The pins 17 are conveniently rounded at their ends that protrude from the hole 18 and pass through the shoulders of the end 15, which conveniently has a U-shaped cross-section and is made of metal, in suitable longitudinal slotted holes 15a. The pins 17 are suitable to fit in corresponding seats 23 of shoulders 24 which are substantially parallel and between which the end 15 is suitable to be inserted and guided; said shoulders extend from a base 25 made of plastics which is fixed to the plate 11 by means of screws 26. The two shoulders 24 diverge at the region where the end 15 is inserted, so as to guide said end in the right direction for insertion. An elastic wing 27 is formed on said base 25 in the region where the end 15 rests; said wing is raised from said base and constitutes an element for elastically coupling the back 10 and the support 16. From what has been described above it is therefore evident that the back can be assembled completely, by fixing the base 25 inside it, and can then be coupled to the support 16 simply by inserting the end 15 with the pins 17 between the shoulders 24 through the opening 14 of the shell 13. This allows to eliminate considerable problems which currently occur in the field as regards assembly, adding advantages linked to easier storage and transport. In practice it has been observed that the intended aim and objects of the present invention have been achieved. In practice, the materials employed, so long as they are compatible with the contingent use, as well as the dimensions, may be any according to the requirements. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims: Device for fixing the back of a chair or the like to the supporting structure comprising, at the end (15) of a vertical portion of the support (16) of the back, two oppositely arranged elastically retractable pins (17) which are suitable to fit in corresponding seats (23) of shoulders (24) which extend from the internal structure (11) of the back (10), said end (15) being insertable between mutually facing sides of said shoulders (24), characterized in that said shoulders (24) comprise on said facing sides thereof guiding channels for said pins (17), said guiding channels divergingly extending along said sides from said seats (23) downwardly to a region where said end (15) is insertable so as to force said pins (17) to retract gradually while guiding the end (15) upwards until the pins (17) are received and locked in said seats (23). Fixing device according to claim 1, characterized in that said retractable pins (17) protrude from a transverse through hole (18) of an element (19) which is fixed to said end (15), said pins (17) having corresponding wider ends (20) that are slideable in a wider median region of said hole (18), a spring (22) being arranged between said wider ends (20). Fixing device according to claim 1, characterized in that said shoulders (24) extend from a base (25) which is fixed to the supporting structure (11) of the back. Fixing device according to one or more of the preceding claims, characterized in that said element (19) which is fixed to said end (15) is locked at an inclined face defining a stop element of said support (16). Fixing device according to one or more of the preceding claims, characterized in that an elastic wing (27) rises from said base (25) in the region where said end (15) of said support rests, said wing (27) constituting a springing element for said back (10). Fixing device according to one or more of the preceding claims, characterized in that said end (15) of the support of the back is made of metal and has a U-shaped cross-section, said pins (17) protruding between longitudinal slotted holes (15a) of the wings of said end (15) of the support. Fixing device according to one or more of the preceding claims, characterized in that said base (25) is concealed by a covering shell (13) and can be accessed, for the insertion of said end (15) of the support, through a corresponding opening (14) of said shell.

Inventors: CITTON NAPOLEONE, CITTON, NAPOLEONE
Applicants: CITTON & C S A S N, N. CITTON & C. S.A.S.
Application year: 1994
Main classification: A47C7
IPC codes: A47C7